Simultaneous Parameter Identification of Synchronous Generator and Excitation System Using Online Measurements

In this paper, a new method is presented to simultaneously identify parameters of synchronous generator and its excitation system (EXS) using measurement data. These measurements could be provided by metering devices such as data acquisition system or fault recorders of the power plant. Since a smart grid is capable of providing synchronized measurements using phasor measurement units, the desired data could also be provided by these devices. In the proposed method, the reference voltage of the EXS is considered as the input signal, while the terminal voltage and output active power of the machine are considered as output signals. The desired parameters are classified into three categories using a sensitivity analysis: 1) the parameters that affect the terminal voltage; 2) the parameters that affect the active power; and 3) the parameters that do not considerably affect either. A multistage genetic algorithm optimization is used to iteratively identify the parameters. To show the effectiveness and accuracy of the proposed method, it is applied to a single machine with a dc-type EXS connected to an infinite bus. Using the proposed method, 19 parameters of synchronous generator and its EXS are identified within four stages.